midimap: Allow GetVolume by device identifier

[Paul Vriens]

On 03/19/2010 10:52 AM, Joerg-Cyril.Hoehle at t-systems.com wrote:
> Hi,
>
> this patch does not include a work-around for Paul Vriens' real XP box
> which returns INVALPARAM for both variants of midiOutGetVolume on
> the Creative driver.  I'd like to sample test.winehq first to see how
> common this error is first.
> Paul, did you isolate the exact reason for the BSOD on winme?

Not yet. That BSOD was only in the CALLBACK_FUNCTION case (not the 
current default in the tests).

-- 
Cheers,

Paul.